Commercial refuse bins are usually large and of a rectangular shape for handling by mechanized refuse trucks. Heretofore, such large rectangular receptacles have been made from an open steel container with a flat metal or plastic lid in order to seal the contents. Such large containers typically have either rear or front loading and often provide hinged covers which can be raised to receive refuse, as well as automatically opening when the container is dumped by being lifted and overturned by refuse truck. The container lid or cover is an important component of these large rectangular refuse receptacles because they normally are required to hold refuse for at least several days or a week. For sanitary and other related reasons, it is necessary for the refuse container to be closed in order to minimize the escape of odors which would attract undesirable small animals. Since these refuse container must be lifted and turned over for dumping into a refuse truck, it is desirable that the refuse container be both strong and as light weight as possible. Covers have been made of steel but they have not proven satisfactory, as they are heavy, noisy, awkward to work with and become unsightly after a few months use.
As a replacement for steel or other metal covers, the prior art discloses refuse covers that are made as a one piece molded plastic cover. U.S. Pat. No. 4,158,424 to Carmack discloses a rubbish bin lid which has a flat surface and a projecting portion depending downward, a well as another portion projecting upward. The Jungles U.S. Pat. No. 4,342,402 is directed to a one piece planar molded plastic cover having embossed portions defining hinge structures along the rear edge and space transverse ribs across the width, and a longitudinal rib merged into the transverse ribs on one side of the cover. The Fagliano reference (U.S. Pat. No. 4,151,928) discloses a deformed and generally planar central section on the trash bin cover, which is made from polymer material. Also, U.S. Pat. No. 4,445,623 to Kolling et al. discloses a one piece plastic trash container having stiffening ribs along one side of the plastic trash container cover.
Although the preceding references attempt to provide a viable plastic cover, none of the prior art designs exhibit the strength and durability which approach these characteristics as exhibited by the heavier steel lids which they were intended to replace. It is further noted that the plastic lids of the prior art tend to sag and deform when subject to intense sun and high ambient temperatures. This of course defeats the purpose of the lids, which is to contain odors, and to block access to the containers by vermin and rodents. Further, when the prior art plastic lids were propped open they would often tend to bend down to a nearly closed position, so that the user would have to use one hand to raise the drooping lid while trying to deposit refuse.
Accordingly, a principal object of the invention is to provide a container cover for use in conjunction with commercial refuse containers, which is both lightweight and strong, having the durability of a heavyweight metal cover, and which avoids the problems outlined hereinabove.